The present invention relates to packaging for fluid products and the like, and in particular to a dispensing package and method for making the same.
Many different types of packages or containers are presently available for packaging non-solid products of the type which are capable of flowing, such as fluid or fluidized materials, including liquids, pastes, powders, and the like, which substances are collectively and generically referred to herein as "fluids". Some such packages include a dispenser which permits a selected amount of fluid to be discharged from the package, and then reseals to close the package.
Self-sealing dispensing valves have been used in packaging for certain types of products, such as the container disclosed in U.S. Pat. No. 4,728,006 to Drobish et al, which is designed for shampoos, conditioners, and the like. However, such valves have been known to experience some types of sealing problems, and inconsistent dispensing characteristics, particularly when the packages are exposed to significant temperature variations.
Liquid silicone rubber valves have recently been used in some types of packaging, and have proven particularly advantageous since the material is inherently quite inert, and will therefore not either adulterate or react with the packaged product. Examples of such packaging are provided in Applicant's U.S. Pat. Nos. 5,033,655; 5,213,236; 5,377,877 and 5,409,144 to Brown et al, which are incorporated herein by reference.
Although liquid silicone rubber possesses many attributes for use in packaging, it also has other characteristics which render such applications problematic. For example, the surfaces of liquid silicone rubber parts are extremely tacky or sticky, having a very high coefficient of friction. As a result, handling the same is difficult, and in attempting to attach a dispensing valve to a container by a conventional threaded collar arrangement, the surfaces of the valve flange will stick tightly to the adjacent surfaces of the container and collar before the collar can be tightened securely enough to create a leak-resistant seal. Tightening of the collar often causes the valve flange, as well as the entire valve to distort from its designed shape, thereby preventing the formation of a secure seal, and/or changing the intended dispensing and sealing characteristics of the valve.
Another drawback associated with the use of liquid silicone rubber in dispensing valves for product packaging is that it cannot be heat fused. Also, there is presently no available technology to quickly and reliably adhere a liquid silicone valve to a container, at least without substantial preparation, so as to render high speed commercial assembly impractical at this time.